The invention relates to orthotic braces and more particularly to pivotal leg and foot orthotics designed to permit plantarflexion and dorsiflexion while at the same time restricting inversion and eversion of the foot.
Due to the growth in popularity of sports participation there has been a subsequent growth in sports injuries, among them are ankle sprains and strains caused by excessive inversion or eversion of the foot. Those who suffer from such ankle injuries need an ankle brace which will allow them to rehabilitate the ankle by restricting the turning in and turning out, known as inversion and eversion, of the ankle but will allow free movement up and down of the ankle, known as dorsiflexion and plantarflexion. Such a brace needs to allow a user to continue walking or continue participating in athletic activity, if desired, and offer someone with weak ankles extra support. In short, a brace is needed which permits rotational movement through the axis of the ankle joint while restricting sideways bending movement perpendicular to the axis of the ankle joint. Such brace should also provide shock absorption and be comfortable, lightweight, unobtrusive, simple and inexpensive.
In the past such purposes have been achieved through the use of plastic or cloth foot and ankle members connected with a pivot joint, which allow rotational movement and restrict lateral movement but have little in the way of shock absorption and could allow rubbing and chafing of the lower leg if the leg is not properly wrapped. Such braces are often only wearable outside of the shoe and trousers, or cannot be worn with shoes or normal trousers at all, causing embarrassment and inconvenience to the wearer.
Additional braces allow for greater shock absorption and comfort, but in doing so, have complicated mechanisms joining foot and ankle members that are intricate, bulky and can be binding. Such braces are worn outside of the shoe and trousers or cannot be worn at all with shoes and trousers, again leading to embarrassment and inconvenience as the braces mentioned previously. Increased comfort has been achieved through greater flexibility laterally at the ankle joint, but this is not desirable when inversion and eversion are to be restricted. The joining mechanisms, being complicated, are more difficult to manufacture and therefore more expensive and more difficult to maintain.
Other braces attach directly to the wearer""s shoe. These are not concealable, could damage the shoe they are affixed to and depend for strength, in part, on the shoe itself. The jointing mechanisms are also delicate, binding and pinching to material near the jointing mechanism.
Postoperative and post-injury braces are available which restrict inversion and eversion. These braces can have adjustments to allow some rotation of the ankle joint, but rotation is limited to a degree if not restricted altogether. Such braces are very bulky, heavy, unsightly and will allow only restricted plantarflexion and dorsiflexion of the foot. Such braces are not particularly designed for the purposes outlined above.
There is, thus a need for an ankle foot orthotic that is lightweight, strong, wearable inside of the shoe and trousers, simple to construct, use and maintain, comfortable and economical while at the same time permitting dorsiflexion and plantarflexion, restricting inversion and eversion of the foot and also providing a means of shock absorbency for the further comfort of an injured or healthy wearer participating in athletic activity, walking or rehabilitating.
The present invention is directed to an ankle-foot orthotic that is lightweight, strong, wearable inside of the shoe and trousers, simple to construct, use and maintain, comfortable and economical while at the same time permitting dorsiflexion and plantarflexion, restricting inversion and eversion of the foot and also providing a means of shock absorbency for the further comfort of an injured or healthy wearer participating in athletic activity, walking or rehabilitating.
An ankle-foot orthotic having features of the present invention comprises a foot shell and a lower leg shell. The foot shell is pivotally attached to the lower leg shell employing a hinging means which permits rotational and translational movement of the foot shell relative to the lower leg shell. The hinging means also restricts sideways bending movement of the foot shell relative to the lower leg shell. The permitting of rotational movement allows desired dorsiflexion and plantarflexion of the foot to occur. Permitting translational movement allows up and down movement of the lower leg brace relative to the foot brace and provides shock absorbency to the orthotic and comfort for the wearer. The restriction of sideways movement prevents undesirable and injury causing excessive inversion and eversion of the foot.
The hinging means comprises a lateral mechanical joint located at the outside of the wearer""s ankle and a medial mechanical joint located at the inside of the wearer""s ankle. Each mechanical joint comprises a housing, a slider, a cover, a spring means and a pivoting means. The housing is hollow with an open face and a partially open end. The slider is positioned freely inside of the hollow cavity of the housing and is shaped to project through the partially open end of the housing but shaped not to be removable through the partially open end. A cover is affixed over the open face of the housing that in one embodiment of the invention is secured to the housing with screws. With the cover in place, the slider is rigidly held inside of the housing, thereby allowing only restricted side to side movement of the hinging means perpendicular to the ankle joint. Spring means are positioned inside of the housing which provide cushioning during translational movement of the slider, and the ankle-foot orthotic as well, while also allowing the slider and ankle-foot orthotic to return to a neutral position when neither upward or downward forces are being applied to the wearer""s foot or leg. A pivoting means is attached to the end of the slider projecting through the partially open end of the housing thereby providing rotational movement to the ankle-foot orthotic.
The foot shell of the present invention is made of a plastic material that is molded in a thin layer to a wearer""s foot so that the foot, with foot shell attached, can easily fit within the wearer""s shoe. The foot shell comprises a lower plate on which the sole of the foot rests, an upright lateral sidewall adjacent to the outside of the foot and extending upward to the axis of the ankle joint where it flares away from the ankle to accept the fitting of the pivoting means, an upright medial sidewall adjacent to the inside of the foot and also extending upward to the axis of the ankle joint where it flares away from the ankle to accept the fitting of the pivoting means, and a rounded posterior wall in which the heel of the wearer is enclosed. The lower leg shell is likewise made of a plastic that is molded in a thin layer to a wearer""s lower leg from slightly above the ankle joint to below the knee so that the lower leg, with leg shell attached, can easily fit within the trouser leg of the wearer. The lower leg shell comprises a vertical lateral sidewall adjacent to the outside of the leg having a top and a bottom end, the bottom end being flared away from the leg to accept attachment of the hinging means, a vertical medial sidewall adjacent to the inside of the leg having a top and a bottom end, the bottom end being flared to accept attachment of the hinging means, a vertical rounded posterior wall having a top end and a bottom end adjacent to the rear of the leg and hooked fabric attachment material adhered to the top end of the lower leg shell to secure the lower leg shell to the wearer""s leg.
The lateral mechanical joint is fixedly attached to the flared bottom end of the vertical lateral sidewall of the lower leg brace with screws and pivotally attached to the flared upright lateral sidewall of the foot shell. The medial mechanical joint is fixedly attached to the flared bottom end of the vertical medial sidewall of the lower leg brace with screws and pivotally attached to the flared upright medial sidewall of the foot shell. In this way, both rotational movement and translational movement are provided to the foot-ankle orthotic while sideways bending movement is restricted.
The pivoting means of the present invention is comprised of a bolt which passes through a hole defined through the end of the slider that projects out of the partially open side of the hinging means housing, and passes through the upright lateral or upright medial sidewall of the foot shell. A retaining nut, threaded onto the end of the bolt secures the slider to the foot shell and thereby allows rotational movement.
The spring means of the present invention is comprised of elastic rubber material that is placed above and below the end of slider that is positioned inside of the housing. When translational, upwards or downwards, movement of the slider occurs perpendicular to the axis of the ankle joint, depending on the force applied, then a return to a neutral position is facilitated by the elastic rubber material when the force causing the movement is removed. In this manner shock to the foot and ankle is absorbed by the foot-ankle orthotic. Wearer comfort is also aided, as rubbing of the leg by the orthotic is decreased, since the upper shell can move translationally with the leg instead of remaining stationary and scraping the lower leg.